This project was initiated to evaluate the relationship between chemically induced mutagenesis and carcinogenesis. The primary emphasis is placed on antitumor agents and known environmental contaminants and model chemical carcinogens. A sensitive in vitro bacterial test system is used for the detection of chemical mutagens. The research is directed at present to determine: (1) the role, if any, of metabolic activation in the mutagenesis caused by antitumor agents and chemical carcinogens; (2) the effect of structural modification on the mutagenicity of both antitumor agents and model chemical carcinogens; (3) the feasibility of using nucleophiles such as L-cysteine, N-acetyl-cysteine and cysteamine to inhibit mutagenicity of the above mentioned compounds. BIBLIOGRAPHIC REFERENCES: Dybing, E. and Thorgeirsson, S.S.: Metabolic Activation of 2,4-Diaminoanisole, a Hair-Dye Component - I. Role of Cytochrome P-450 Metabolism in Mutagenicity In Vitro. Biochemical Pharmacology. 26: 729-734, 1977.